Crystal detector for radio apparatus



Sept. 16 T924;

.E. c. R'owL Y -CRYSTAL DETECTOR'FOR RADIO APPARATUS Filed Dec.

atent Sept. 16, 19 24.

mreo srA'rEs EUGENE O. BOWIiEY, F SEATTLE, WASHING-TON.

CRYSTAL DETECTOR FOR RADIO APPARATUS.

Application filed December 27, 1922. Serial No 609,292.

To all whom it may concern Be it known that I, EUGENE C. Rownnr,

a citizen of the United States, residing at Seattle, in the county of King and State of- Washington, have invented certain new and useful Improvements in- Crystal De-' tectors for Radio Apparatus, of which the following is a specificatiom .My invention relates to a crystal detector for radio apparatus and particularly to an improvement .in that'part of the detecting apparatus which is known in the only so much of a radio receiving set is ilart as the cats whisker.

The invention has for its particular object to improve this element of crystal de tector sets, which in practice is employed to locate the radio active spots or points on the crystal and convey the audio waves to a telephone or other instrument designed to 2 make audio frequency audible to the ear.

In heretofore known devices of this type it has been customary to provide a single wire which is adapted to be moved about the face of the crystal to locate the radioactive spots, and in contra-distinction. to this, my invention contemplates a detecting device comprising a plurality of wires, the invention being capable of being used with any number of wires whereby a plurality of points on the crystal receiving the audio waves may beengaged-by the detecting device and the efficiency of the same manifestly increased.

My invention is capable of adaptation to most of the known commercial types of crystal detectors now on the market and is furthermore so constructed as to enable the same to be varied and modified without the aid of a person particularly skilled in the art to adapt it to the type of crystal detector at hand, and the purpose and. duty for which it is to be employed. 7

The invention will be made more apparent as the description proceeds, especially when considered in connection with the accompanying drawings wherein;

Figure 1 is a side elevation of a crystal detector with my invention applied thereto; Fig. 2 is a top elevation of the structure illustrated in Fig. 1; I

Fig. 3 is an end elevation of the detector;

' ously this structure may be changed to suit the particular designs of the manufacturer.

Fig. 4 is a fragmentary side elevation of the same; 1 Fig. 5 is a detail perspective view of the same; Fig. 6'is an end .view indicating the manner. in which the detecting wires may be multiplied; and, Fig, 7 is-a detail perspective view showing a slight modification of the detector which is capable of attachment to detector sets already in commercial use.

At'the outset it-should be understood that lustrated as is necessary to show the appli cation of my invention, and that the type I of crystal detector set'herein described and shown in the drawings is for illustrative purposes only, 'it being obvious as, the description proceeds that the invention is applicable with an equal degree of efliciency to practically all types of cry a1 detectors In the drawings I have s owna crystal detector having a base 10 upon which are supported a pair of postsll and 12. A pair of: binding posts '13 are provided, electrical connection being established between one of the posts 11 and a binding post 13 by means of an electrical conductor 14, and from the other post 12 to the other of the binding posts 13 by an electrical conductor 15. -These electrical conductors, 14 and 15,

are preferably disposedin a recess formed on the under side of the base 10, but obvi- Secured to one of the posts, and in the il- 7 lustrated example herein shown, the post 11, is a crystal cup 16, which is adapted to receive the crystal 17, this crystal projecting slightly from the open side of .the crystal cup 16, as clearly illustrated in Figs. 1 and 2. i

In practice it hasbeen customary to provide a single fine wire movable over the face of the crystal, this wire being known in the art as the cats whisker. By my invention I contemplate modifying this arrangement and to provide instead a plurality of wires which may be caused to engage the face of the crystal to search out or locate the radio improved type of detecting apparatus I provide a disc 18 apertured centrally thereof for the reception of a rod 19, the rod 19 having a head 20 which engages the disc 18. The disc 18 is formed with a plurality of notches ,orrecesses' 20 arranged around its periphery and a plurality of apertures 21 'arranged in a circumferential row adjacent the periphery of the disc.

In plurality of U-shaped wires 22, which are passed through the apertures 21 of the disc 18 and project from one face of the disc at right angles to the plane of the same. The number of these U-shaped wires may be varied according to the type of detector set employed, and the purpose of theoperator, it being possible to provide, for instance, eight points, as illustrated in Fig. 5, or sixteen points,as illustrated in Fig. 3. It is also possible to mount suflicient of the U- shaped wires upon the disc 18 so as to provide thirty-two points, as suggested in Fig.-

6. In the first instance four of the U-shaped wires will be mounted upon the disc, these wires being inserted through pairs of the apertures 21. y

In Fig. 3 eight of the U-shaped wires are I illustrated, these U-shaped wires having one leg passing through the apertures 21, while the other leg passes through the notches 20 arranged around the periphery of the disc. In this instance sixteen detecting points are provided.

As suggested in Fig. 6 thirty-two detecting points may be provided by inserting the U-shaped wires with the adjacent legs of the U-shaped wires through the same slot, and by further mounting a set of U-shaped wires with one leg thereof extending through the apertures 21 and the other leg extendingthrough the notches 20.'

.Obviously, any number of points under eight may be provided by varying the number of U-shaped wires mounted upon the disc 18.

After the wires have been mounted upon the disc in a number sufficient to provide the number of wire points required, there is slipped upon the shaft 19 an apertured disc 23 which will herein be termed the binding disc. The shaft 19 adjacent its head 20 is externally threaded to receive a clamping nut 24 whereby the disc 23 may be pressed against the bases of-v the U+shaped wires to firmly clamp the same in place. 7 In practice itis customary to interpose'a spring 25 betweenthe nut 24: and the supporting post 12 upon which the shaft 19 is mounted, and to provide on the end of the shaft 19 a handle 26. It is also customary to so mount the shaft '19 that the end carrying the wires which engage the crystal is capable of a swinging or swivelled movement ractice I.contemplate employing a.

whereby the wires may be caused to en age the entire exposed surface'of the crysta 17 While from the description of my invention noted hereinbefore it has been explained how it is possible to mount a sufficient number of wires onto the plate 18 so as toprovide thirty-two points, still in practice it has been found that from eight to sixteen points are most eflicient, as too many points present too solid a surface to the crystal and thus the best results are not obtained. Obviously the spring will hold the detector wires into engagement with the crystal surface, and by providing a multiplicity'of detecting points the radio active point may be found with considerable greater ease and in less time, and furthermore theconnection vided a stub shaft 27, a clip 28 being clamped preferably between the nut 24 and the clamping disc 23, and an operating rod 29 being fixed to the clip 28 for operating the detector head. In this manner a detector head constructed in accordance with my invention and provided witha multiplicity of wires may be connected to the han- -dle which carries in commercially known sets the single cats whisker.

Obviously the size of the wires 22 may be varied and after they have been clamped onto the disc 18the ends thereof may be cut so .that the-wires will project from this disc the desired length. Also it is possible to spread the wires, inasmuch as they are easily bendable, thus presenting to the crystal a detecting head of the size and shape de sired.

Obviously, with a detector constructed in accordance with my invention a more durable structure is obtained, inasmuch as the necessity for loose connections or coiled wires or the like is eliminated. By. presenting to the crystal a larger surface composed of a plurality of wires, the spring 25 may be of such strength as to hold the detector head against the crystal against displacement by ordinary jars. Furthermore it has been found that inasmuch as it is not necessary to see the crystal in order to find its radio active points a detector constructedin accordance with my invention may be enclosed in a tube or a cabinet, leaving exposed only the handle for adjusting the be unnecessarily limited as to details of construction but reserve the ri ht to make such changes as may come wit in the purview of the accompanying claims.

whiskers secured between said disks.

2. A crystal detector element comprisin a conducting disk, a clamping disk an means for securing the same to said first named disk, and a plurality of wires mounted between said disks to provide a plurality of contact points.

3. A crystal, detector element comprisin a conducting disk, a clamping disk anc l means for securing the same to said first named disk, a'plurality of wires mounted between said disks to provide a plurality of contact points, and means for mounting said detector element adjacent the crystal.

4. A detector for use in combination with radio crystal detector sets comprising a disc provided with a pluralit of apertures'and peripheral notches, a urality of wires adapted to be removab y mounted on said disc by extending throu h said apertures and notches and means or clamping said wires to said disc.

5. A detector for use in combination with radio c stal detector sets comprising a disc provide with a plurality of apertures and peripheral notches, a plurality of U-sh'aped wiresadapted to be removably mounted on said disc andto extend through said apertures'and notches, a headed shaft passing axially through said disc, a clamping disc on said shaft for holding said U-shaped wires in place and a binding nut engagmg said clamping disc.

6. In a radlo crystal detector set a detector comprising a disc provided with a plurality of apertures and ripheral notches, a plurality of U-shape wires adapted to extend through said apertures. and notches and-to project from one face of said disc, ashaftfor said disc, a clamping disc engaging said wires, a binding nut on said shaft, means.

for mounting said shaft so as to position said detector adjacent said crystal and spring means for holding said detector in en agement with said cv stal.

n testimony whereof aflix mysignature.

EUGENE c. nownnr. 

